Problem: At the market, $8$ apples cost $\$4$. How much do $9$ apples cost? $\$ $
Answer: We're trying to find the cost of $9$ apples. $1$ $\longrightarrow$ $\$0.50$ ${8}$ $\longrightarrow$ ${\$4.00}$ $ \div 8\ $ $ \div 8\ $ ${apples}$ $\longrightarrow$ ${ cost}$ If ${8}$ apples cost ${\$4}$, then $1$ apple costs $\$0.50$. $9}$ $\longrightarrow$ ${\$4.50}$ $1$ $\longrightarrow$ $\$0.50$ $ \times 9\ $ $ \times 9\ $ ${8}$ $\longrightarrow$ ${\$4.00}$ ${apples}$ $\longrightarrow$ ${ cost}$ So, $9}$ apples cost ${\$4.50}$.